1. Field of the Invention
This invention relates to oil soluble additive mixtures useful in fuel and lubricating oil compositions, including concentrates containing said additives, and methods for their manufacture and use. The additive mixture comprises an ashless non-borated dispersant, copper carboxylate antioxidant, and ashless rust inhibitor.
2. Description of the Prior Art
European Patent 24,146 relates to lubricating compositions containing oil-soluble copper compounds in an amount sufficient to retard or inhibit oxidation of the lubricant during use (5 to 500 ppm Cu), and discloses that such lubricant compositions can further comprise from 1 to 10 wt. % ashless dispersant compounds. Preferred are dispersants derived from polyisobutenyl succinic anhydride and polyethylene-amines, which dispersants can be further modified with a boron compound to provide about 0.1 to 10 atomic proportions of boron per mole of the acylated nitrogen compound. In addition, the patent discloses that the lubricant compositions can also contain rust inhibitors such as lecithin, sorbitan monooleate, dodecyl succinic anhydride or ethoxylated alkyl phenols; and other additives such as pour point depressants, viscosity index improvers, other antioxidants (e.g., zinc dialkyldithiophosphates), basic alkaline earth metal detergents, etc. Illustrative of oil-soluble copper compounds are copper dihydrocarbyl thio- or dithio-phosphates, copper salts of a synthetic or natural carboxylic acid (e.g., C.sub.10 to C.sub.18 fatty acids, oleic acid, naphthenic acids) and the like.
U.S. Pat. No. 4,552,677 relates to compositions comprising copper salts of substituted succinic anhydride derivatives containing a hydrocarbon-based substituent group containing from about 8 up to about 35 carbon atoms, which the patentee indicates are effective antioxidants for crackcase lubricants and which avoid a deleterious effect on rust observed by the patentee using copper oleate as antioxidant. The patentee, referring to British Patent No. 2,056,482 (equivalent to European Patent 24,146, discussed above), describes copper oleate antioxidants as causing degradation of the rust performance properties of lubricants, which performance can be improved by employing the '677 patentee's copper-substituted succinic anhydride derivatives.
U.S. Pat. No. 3,509,052 relates to lubricating oil compositions containing a lubricating oil, a dispersant (which is a derivative of a substituted succinic acid where the substituent contains at least 50 aliphatic carbon atoms), and a demulsifier, e.g., polyoxyalkylene polyols, together with other additives, such as rust inhibitors, oxidation and corrosion inhibitors. The dispersant is said to also permissibly comprise boron post-treated alkyl-substituted succinimides, or metal salts of substituted succinic acids (wherein the metal is preferably a Group I or II metal, Al, Pb, Sn, Co, Ni or Zn).
European Patent 92,946 relates to the combination of oil-soluble copper compounds with glycerol fatty acid esters as fuel economy additives.
U.S. Pat. No. 2,356,661 deals with lubricating oils containing 50 to 100 parts per million of copper together with an oil-soluble organic sulphur compound to provide more stable lubricants which can be employed in internal combustion engines over longer periods of time without causing objectional increase in the viscosity of the oils and with the formation of less deposits in the engine and with less corrosion of sensitive bearing metals.
U.S. Pat. Nos. 2,343,756 and 2,356,661 disclose the addition of copper compounds, in conjunction with sulfur compounds, to lubricating oils. In U.S. Pat. No. 2,552,570, cuprous thiophosphates are included in lubricant compositions at relatively high levels, which results in undesirably high sulfated ash content. In U.S. Pat. No. 3,346,493, a wide variety of polymeric amine-metal reactants are employed as detergents in lubricant compositions. In the two isolated instances in which the metal is copper and the composition contains zinc dihydrocarbyldithiophosphate, either the amount of copper employed is outside the range of the present invention or it is necessary that the oil insoluble copper compound be complexed with the dispersant. U.S. Pat. No. 3,652,616 discloses a wide variety of polymeric amine-metal reactants for addition to lubricating compositions. U.S. Pat. No. 4,122,033 discloses the entire group of transition metal compounds as additives for lubricants.
U.S. Pat. No. 3,271,310 relates to metal salts of alkenyl succinic acid, which are disclosed to be useful as detergents and rust inhibitors in hydrocarbon oils and which comprise metal salts of a hydrocarbon substituted succinic acid having at least about 50 aliphatic carbon atoms in the hydrocarbon substituent wherein the metal comprises Group I, Group II, aluminum, lead, tin, cobalt or nickel. The salts are disclosed to be useful in lubricating oils in amounts of from 0.1 to about 20 wt. % and in lubricating compositions for using gasoline internal combustion engines in an amount of from 0.5 to about 5 wt. %. The salts are disclosed to be useful in combination with ashless dispersants, including those which have been borated by reaction with boric acid. Further, the salts are indicated to be useful as emulsifying agents in water in oil emulsions, and that when so employed, other emulsion additives such as rust inhibitors can be used.
U.S. Pat. No. 3,351,647 relates to the phosphorus and nitrogen containing reaction products formed by reacting a metal salt of a phosphinodithioic acid with an amine such as an aliphatic amine having from 1 to about 40 carbon atoms. Copper is among a group of metals disclosed to be useful. The compositions are disclosed as additives for lubricating oils and automatic transmission fluids, in which they act as oxidation inhibitors and anti-wear agents. These compositions are stated to be useful in combination with ashless detergents such as the reaction product of triethylenetetraamine with an alkenyl substituted succinic anhydride having at least 50 carbon atoms in the alkenyl substituent.
U.S. Pat. No. 3,401,185 relates to metal salts of phosphorus acids, including copper salts of such acids, useful in lubricating oils in combination with ashless dispersants which may be borated.
U.S. Pat. No. 3,328,298 relates to metal (e.g., copper) containing compositions formed by reacting a basis inorganic metal compound with an intermediate formed by reacting a phosphorothioic acid diester with an equimolar amount of an epoxide. The resulting metal containing compositions are disclosed to be useful in combination with ashless dispersants.
U.S. Pat. No. 4,417,990 relates to mixed metal salts/sulfurized phenate compositions.
U.S. Pat. No. 4,664,822 relates to certain copper ore based metal containing compositions which are disclosed to be useful in combination with other additives, among which ashless containing dispersants (which can be borated), zinc dialkyldithiophosphates, ash-containing detergents, and ashless rust inhibitors are mentioned.
Canadian Patent 1,189,307 relates to hydrocarbon soluble compositions containing a transition metal salt of an organic acid, a hydrocarbon soluble ashless dispersant and a phenolic antioxidant, which composition can additionally comprise dyes, metal deactivators, and, particularly, demulsifying agents. The transition metal salts mentioned include copper organic salts, and the organic acids include carboxylic acids, sulfonic acids and phosphorus acids. It is indicated that the transition metal salts used in the invention are often overbased and contain an excess of one equivalent of metal per equivalent of acid derived moiety.
U.S. Pat. No. 4,552,677 relates to copper salts of hydrocarbyl substituted succinic acids wherein the hydrocarbon group contains from about 8 to about 35 carbon atoms. Such copper salts are said to be effective antioxidants for crankcase lubricants without the deleterious effect on rust and copper/lead bearing corrosion performance that accompanies copper oleate, which is described in European Patent 24,146, discussed above. The copper salts of the '677 patent are said to be useful in combination with other additives including ashless dispersants which may be borated.